I. Field of the Disclosure
The technology of the disclosure relates generally to physical transmission media, and particularly to a physical layer (PHY) within a protocol stack.
II. Background
Computing devices are prevalent in contemporary society. Such computing devices benefit from an increasing array of functionality being made available by virtue of increasingly complex integrated circuits. Such integrated circuits may be positioned on a printed circuit board and interconnected through non-transitory conductive elements, for example, physical traces. Signals are routed onto these physical traces according to variations of the Open System Interconnection (OSI) model. The OSI model defines various abstraction layers, which encapsulate a digital payload. The lowest level of the model is the physical layer or PHY, which is responsible for converting the digital bit stream into an analog or pseudo-analog signal capable of being transmitted on the physical trace. While such communication may take place between integrated circuits on the printed circuit board, smaller scale physical traces may exist within the integrated circuit and may also have OSI stacks with their own PHY associated with signals routed across these interior traces.
Different PHY may have different “rules” associated therewith. For example, one PHY may have predefined voltage levels larger or smaller than a second PHY. Circuit designers may choose a particular PHY based on assumptions about how the circuit will operate within a computing device. For example, if a relatively short distance is traversed by a physical trace, a lower power PHY may be selected as compared to situations in which a longer trace must be traversed.
However, it is not uncommon for a single integrated circuit to be used in multiple different environments. For example, such an integrated circuit may be used in a smart phone as well as a tablet. While the integrated circuit may use a PHY optimized for one environment based on the assumptions of the designer, the PHY may not be optimized for the second environment. Likewise, even within a single environment, there may be environmental or operational circumstances which change the operating conditions of the traces and make a particular PHY more or less attractive. For example, if a transceiver with a high speed frequency synthesizer is selectively activated and put to sleep, the frequency synthesizer may create electromagnetic interference (EMI) in the environment of the traces via conductive or radiated means, but only when the frequency synthesizer is active. Likewise, the signals on the traces may act as EMI aggressors for other elements within the computing device. Accordingly, there is a need to be able to improve the flexibility of the PHY after installation within a computing device.